Cannabinoids are the class of drugs found in marijuana. These drugs have been used throughout history for medicinal and recreational purposes. Despite a long history of use, an understanding of the mechanism of cannabinoid action is just beginning to emerge. The natural role of cannabinoids is also not well understood but may be related to motor function, pain perception, learning and memory. The importance of understanding the role of cannabinoid signaling is increasing as marijuana and cannabinoids are more seriously considered for wider medicinal use. Better understanding of cannabinoid activity is dependent upon development of model systems that will allow investigation of specific aspects of cannabinoid effects. The zebra finch, a songbird, is a good choice for development of such a model because its singing is a behavior that is learned during sensitive periods of development, similar to human language acquisition. Studying cannabinoid effects on song behavior may allow better understanding of cannabinoid effects on learning and memory over the course of vertebrate development. Preliminary experiments have shown that cannabinoid receptors are expressed in areas of the zebra finch brain known to be involved in learning and maintenance of song behavior. The connections between these cannabinoid receptor-expressing neurons in song regions and neurons in other brain regions will be investigated. Also, the expression of cannabinoid receptors will be investigated over the course of song learning. The effects of exposure of juvenile finches to cannabinoids while memorizing and practicing the reproduction of song will be determined. Finally the cDNA sequence of the zebra finch cannabinoid receptor will be determined and compared to those cloned in other species.